Known opening and closing control device for an opening and closing member of a vehicle drives the opening and closing member of the vehicle by increasing or decreasing an output duty to a driving motor by a feedback control based on a difference between a target speed and an actual speed of the driving motor so that the actual speed is brought close to the target speed. This kind of control device for the opening and closing member of the vehicle is disclosed in Japanese Patent Laid-Open Publication Nos. 6-253570 and 10-257791.
According to each disclosed control device, when pinching of an object is detected at a pinching determination, the motor is reversed so that the object can be surely released from the opening and closing member.
Precisely, according to Japanese Patent Laid-Open Publication No. 10-257791, the ripple of the driving motor is first detected. The actual speed of the driving motor is evaluated by FV conversion of the ripple. Then, the actual speed is differentiated whereby an acceleration of the driving motor is obtained. Further, the torque disturbance applied to the driving motor is evaluated by the actual speed and the acceleration of the driving motor. A change speed of the torque disturbance, which is evaluated by differentiating the torque disturbance, is compared with a determination value for determining the pinching of the object.
The above-mentioned disclosed control device, however, has a complicated structure. Thus, it is considered to determine the pinching of the object by simply comparing a differential value of the actual speed of the driving motor with a predetermined value. In this case, frequency characteristics of the differential value of the actual motor speed are shown in FIG. 5. The gain increases as the frequency increases in FIG. 5. A change amount of the motor speed can be extracted by using the differential. However, an amplitude of a high-frequency based on the noise is larger and thus a peak value of the high-frequency exceeds the predetermined value whereby the wrong determination that the pinching has occurred may be caused as shown in FIG. 6.
Thus, a need exists for an opening and closing control device for an opening and closing member of a vehicle which addresses at least the forgoing drawback associated with other known opening and closing control device for the opening and closing member of the vehicle.